Stamp-mill.



'No. 829,702. PATENTED AUG. 28 1906.- W. W. EDWARDS..

STAMP MILL.

APPLIOATIOfi FILED JAN.15. 1902. RENEWED JAN. 22, 1906.

UNITED STATES PATENT OFFICE.

Specification of Letters Patent.

Patented Aug. 28, 1906.

Application filed January 15, 1902. Renewed January 22, 1906. Serial No.297,219.

To all whom it may concern:

Be it known that I, WILLIAM W. EDWARDS, a citizen of the United States,residing at Los Angeles, in the county of Los- Angeles and State ofCalifornia, have invented new and useful Improvements in Stamp-Mills, ofwhich the following is a specification.

An object of this invention is to provide superior means for rotatingthe stamp while the same is resting on the ore.

Another object is to avoid any tendency of the rotating stamp to turn onthe ore as a pivot and at the same time to provide superior means forretaining the coarse gold, mercury, and amalgam.

The accompanying drawings illustrate my invention.

Fig. 2 is a fragmental detail showing the connection between thestamp-shaft and the spiral gear-wheel which rotates the same. Fig. 3 isa fragmental plan of the stamp-mill. Parts are broken away for clearnessof illustration. Fig. 4 is a view of the die removed. Fig. 5 is afragmental View of the die with shoe partly in section.

In the drawings I have shown only one stamp; but it is to be understoodthat the mill may be furnished with any desired number of stamps.

1 designates a die furnished with a concavity 2 and having at its centera receptacle 3 below the grinding-face of the die and which isdownwardly enlarged, as clearly shown in Fig. 1, for the purpose ofreceiving and holding the mercury, gold, and amalgam. v

4 designates a stamp having a shoe 5 convex at its under side 6 andhaving a hole 7 at the center of its under face. The shaft 8 of saidstamp is grooved longitudinally with a groove 9. 10 designates guidesfor said shaft. 11 designates the usual means for operating the stampvertically.

12 designates a gear-wheel on the stampshaft 8.

18 is a key in the groove 9 and gear-wheel 12.

14 and 15 designate washers serving as means for holding the key inplace in the gear wheel.

16 and 17 designate gear-wheels on opposite sides of the first-namedgear-wheel 12 and meshing therewith to rotate the stamp. Suitable meansare provided for rotating said gear-wheels 16 and 17.

18 and 19 respectively designate thehorizontal shafts on which thewheels 16 and 17 are respectively mounted.

20 and 21 designate gear-wheels on the shafts 18 and 19, respectively,which mesh with each other so that the two shafts are positively rotatedsimultaneously. The power will be applied to either of the shafts 18 or19 by any suitable means.

A belt 22 may be applied to the fly-wheel 23 to drive the same or apulley and fly-wheel (not shown) may be mounted on the shaft 19 and thesame may be driven by a belt. (Not shown.)

24 designates the gear-wheel for driving the cam-shaft 25 to operate thetappet 26 in the usual way.

The above-described construction with horizontal driving-shafts locatedon each side of the stamp-shafts and connected thereto by spiral gearsis extremely advantageous 1n driving a battery of stamps, as the samehorizontal shafts will serve to drive all the stamps of the battery.

The frame of the stamp-mill may be formed of uprights a and the bars I),which form a portion of the guide for the stamp-shafts.

c designates a detachable section which is furnished with a way (i tocorrespond with the way e in the bar I) to form the vertical guides 10for the stamp-shaft. The crossbar and the detachable section or cap 0are furnished with horizontal ways 27, in which the gear-Wheel 12 turns.The cap or removable section 0 may be fastened to the cross bar I) bybolts and nuts f.

The gear-wheels 12, 16, and 17 are spiral miter-gearing and the wheels16 and 17 are mounted on oppositesides of the wheel 12 and are rotatedto simultaneously drive the wheel 12, so that they cause the same to runperfectly true and allow the stamp-shaft 8 to slide therethrough withoutany binding ac tion. When the shaft is rotated by a gear driven on oneside only, such a lateral pressure results that the stamp is not allowedto drop freely and loses part of its force, enough under 1 surface isineffective.

some conditions to largely offset the advantage due to rotation. Inorder to get any advantage from rotation, it is necessary to provide forrotating the shaft without interfering with its vertical movement.

The stamp-mill is preferably geared to rotate the stamp three-fourthsway round while the stamp is resting on the ore. The amount of rotation,however, may be varied within the judgment of the constructor. The holes3 and 7 in the die and shoe, respectively, prevent any possibility ofthe ore at the center of the die acting as a pivot to keep the stampfrom grinding the ore.

In practice with machines of this class the impact of the ordinary dieand shoe only partly pulverizes the ore, and the rotary motion isdepended on to complete the pulverization. Those partly-crushedparticles that are directly or nearly under the center of the shoe arenot affected by the rotary movement of the shoe, and as long as they arenot crushed they prevent further descent of the shoe, such as would berequired to comletely pulverize the ore. This action is Well mown inmachines of this class and is known as pivoting of the stamp by the ore.The parts of the shoe which are farther removed from the center arealone effective in grinding, and it is apparent that if the shoe is heldfrom descent by uncrushed particles at the center even this outer partof the die- My invention is directed to obviating this difiiculty byremoving the central parts of the die and shoe, so that there can be noobstruction offered by the ore to the descent of the shoe except atpoints where the rotary movement thereof is sufiicient to grind awaysuch obstruction.

As the ore is stamped and ground the gold will work to the center andfall into the downwardly-enlarged receptacle 3, in which a suitablequantity of mercury 9 will be deposited. The overhanging walls 72 of thereceptacle 3 prevent the mercury from working out of the receptacle, andthe hole 7 in the center of the shoe serves, together with thereceptacle 3, to form a chamber to receive the materia which otherwisemight pivot the shoe.

It will be understood that in practical operation there will bemaintained in the receptacle 3 a suitable quantity of liquid mercury toabsorb or amalgamate the precious metals and that the usual depth of oreand Water Will be above the die 1. As the stamp 4 descends its shoe 5may force down into the receptacle some of the pieces of ore whichotherwise might pivot the stamp, and the pieces of ore thus forced downinto the receptacle may displace a portion of the mercury and cause suchportion to flow up into the concavity2 and into the interstices be tweenthe pieces of ore in such concavity beneath the stamp. When the stamprises, thus removing the pressure from the ore particles or pieces inthe receptacle, the mercury will flow down the floor of the concavityand into the receptacle, thus displacing from the receptacle the orewhich had dis laced the mercury. It will be understood t at in case thecharge of liquid mercury in the die is sufficient to fill the receptacle3 all the rock or other portions of the ore which have less specificgravity than the mercury will be floated out of the receptacle by themercury when the pressure of the stamp is removed and that when the orehas been crushed to the required fineness it will pass out through thescreens in the usual way. The solid pieces of material that may enterthe hole 7 will fall out as the stamp rises and all material after beingcrushed to the desired fineness will pass out through the screens in theusual way. The precious metals that fall into the mercury in pocket 3become amalgamated and from time to time may be removed, fresh liquidmercury or quicksilver bleing supplied from time to time to take its pace.

In practical operation the stamp is moved up and down and rotated, andthe gold is scoured and kept bright thereby, so as to readilyamalgamate.

I/Vhat I claim, and desire to secure by Letters Patent of the UnitedStates, is-

1. A stamp-mill comprising a die having an open-toppeddownwardly-flaring receptacle in the center of its grinding-face adaptedto receive and retain mercury, a stampshoe having a hole in the centerof its grindroo ing-face, means for vertically reciprocating 1 saidstamp-shoe, and means adapted and arranged to continuously rotate saidshoe.

2. In a stamp-mill, a vertically-reciprocating stamp, means for liftingthe stampshaft and allowing it to drop by gravity,

a gear-Wheel slidingly engaging said shaft and adapted to rotate thestamp, horizontal shafts on opposite sides of said gear-wheel, andgear-wheels on said shafts meshing with the first-named gear-wheel torotate the stamp.

IIO

3. The combination with a stamp-shaft, of n a spiral gear-wheel mountedto turn the shaft,

and slidingly engaging therewith, horizontal shafts on opposite sides ofsaid gear-wheel,

and oppositely-arranged spiral gear-wheels on said horizontal shafts,meshing with the first-named gear-wheel to turn the same. I

4. A stamp-mill comprising a frame having a cross-bar furnished with avertical way for a stamp-shaft and a horizontal way for a gear-wheel, asection furnished with like ways for the shaft and gear-Wheel, astamp-shaft I 2 5 in said vertical ways having a keyway therein, agear-wheel on the stamp-shaft in the two subscribing witnesses, at LosAngeles, gays therefor; a lfley in said dgeafi-wheel ang California,this 8th day of January, 1902.

eyWay, and Was ers on sai s aft in sai gear-wheel Way above and belowsaid gear- WILLIAM EDWARDS Wheel to hold the key in the gear-Wheel Way.Witnesses:

In testimony whereof I have signed my JAMEs R. TOWNSEND, name to thisspecification, in the presence of F. M. TOWNSEND.

